Liquid Crystal Display fixing flicker in 3D image display

ABSTRACT

The present invention proposes an LCD capable of reducing flicker when showing 3D images. The LCD adds a plurality of switch units to every row of scan lines while no additional gate driver is added. The plurality of switch units separately control charging and charge sharing of pixel units, therefore pixel charging and charge sharing are separately controlled. Hence the present invention fixes flicker in 3D image display while no additional gate driver is added.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present Invention relates to a 3D liquid crystal display (LCD), moreparticularly, to an LCD fixing flicker in 3D image display.

2. Description of Prior Art

Human feels images of the real world through what their eyes see. Andhuman brains form the so-called 3-dimension (3D) images according tospatial difference between two different angles reflected in right andleft eyes. The so-called 3D display device imitates prospect of twodifferent angles of right and left human eyes, so that users feel likewatching 3D images while 2D images are actually displayed.

Conventional LCD uses charge sharing to solve color shift. But to LCDswitching from 2D to 3D modes, when 3D mode is initiated, charge sharingis ineffective due to frame inversion, resulting in flicker in 3D image.

More specifically, when LCD is under 3D mode, grey level position isactually a mixture of white and black, i.e. white and black imagesrotate as the first and the second frame alternatively, after mixturewhite and black reflect as grey in human eyes. Take frame inversiondriving method as instance, every frame polarity inverses once. Whiteimage indicates a greater voltage drop with positive polarity, and blackimage indicates a greater voltage drop with negative polarity. Ifcontinuously displaying images like these, LCD is polarized resulting inresidual image.

To fix residual image, a conventional method is change frequency ofinversion from once every frame to once every two frames, which causesdifferent luminance to right and left eyes due to high chargingsaturation of the second polar frame, and meanwhile leaves flickerunsolved.

To fix flicker, separately controlling pixel charging and charge sharingis feasible, i.e. besides scan lines a plurality of driving lines haveto be set up to control charge sharing corresponding to every scan line,which doubles number of gate driver and increases production cost.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an LCD fixing flickerin 3D image display to fix flicker in 3D image display while noadditional gate driver is added.

According to the present invention, a liquid crystal display (LCD)fixing flicker in 3D image display comprises a scan line for sending ascan signal, a data line for sending a grey level signal, pixel unitscomprising a first sub-pixel and a second sub-pixel, a data controllingsignal generator for generating a first data controlling signal and asecond data controlling signal, a controlling signal generator forgenerating a first controlling signal, a second controlling signal, athird controlling signal and a fourth controlling signal, a chargesharing signal source for generating charge sharing signal, a first dataswitch electrically connected to the data line and the first sub-pixel,a second data switch electrically connected to the data line and thesecond sub-pixel, a first switch unit electrically connected to the scanline and the first sub-pixel, a second switch unit electricallyconnected to a constant voltage and the first sub-pixel, a third switchunit electrically connected to the scan line and the second sub-pixel, afourth switch unit, electrically connected to the constant voltage andthe second sub-pixel, and a charge sharing switch, electricallyconnected to the charge sharing signal source. The first data switch isused for conducting the grey level signal to the first sub-pixel whenreceiving the first data controlling signal. The second data switch isused for conducting the grey level signal to the second sub-pixel whenreceiving the second data controlling signal. The first switch unit isused for conducting the scan signal to the first sub-pixel whenreceiving the first controlling signal. The second switch unit is usedfor conducting the constant voltage to the first sub-pixel whenreceiving the second controlling signal. The third switch unit is usedfor conducting the scan signal to the second sub-pixel when receivingthe third controlling signal. The fourth switch unit is used forconducting the constant voltage to the second sub-pixel when receivingthe fourth controlling signal. The charge sharing switch is used forelectrically connecting the first sub-pixel to the second sub-pixel whenreceiving the charge sharing signal and turning on.

In one aspect of the present invention, a process of the scan linesending the scan signal to the pixel units comprises a first period oftime, a second period of time and a third period of time when the LCD isunder 2D image mode. During the first period of time, the first dataswitch, the first switch unit and the fourth switch unit are turned offwhile the second data switch, the second switch unit, the third switchunit and the charge sharing switch are turned off, resulting in thefirst sub-pixel displaying grey level according to the grey levelsignal. During the second period of time, the second data switch, thesecond switch unit and the third switch unit are turned on while thefirst data switch, the first switch unit, the fourth switch unit and thecharge sharing switch are turned off, resulting in the second sub-pixeldisplaying grey level according to the grey level signal. During thethird period of time, the second switch unit, the fourth switch unit andthe charge sharing switch are turned on while the first switch unit andthe third switch unit are turned off, resulting in the first sub-pixelelectrically connecting to the second sub-pixel.

In another aspect of the present invention, the first period of time,the second period of time and the third period of time are successive.

In another aspect of the present invention, the charge sharing signal isthe scan signal. The controlling signal is also generating the fifthcontrolling signal and the sixth controlling signal. The LCD furthercomprises a fifth switch unit electrically connected to the scan lineand the charge sharing switch, and a sixth switch unit electricallyconnected to the constant voltage. The fifth switch unit is used forconducting the scan signal to turn on the charge sharing switch whenreceiving the fifth controlling signal The sixth switch unit is used forconducting the constant voltage to turn off the charge sharing switchwhen receiving the sixth controlling signal.

In another aspect of the present invention, when the LCD is under 2Dmode, the fifth switch unit is turned off while the sixth switch unit isturned on to conduct the constant voltage during the first and secondperiods of time; the fifth switch unit is turned on to conduct the scansignal while the sixth switch unit is turned off during the third periodof time.

In another aspect of the present invention, when the LCD is under 2Dmode, the first controlling signal and the second controlling signal areinversed, the third controlling signal and the fourth controlling signalare inversed, and the fifth controlling signal and the sixth controllingsignal are inversed.

In another aspect of the present invention, when the LCD is under 3Dmode, the fifth switch unit and the sixth switch unit are turned off.

In another aspect of the present invention, a process of the scan linesending the scan signal to the pixel units comprises a fourth period oftime and a fifth period of time when the LCD is under 3D image mode.During the fourth period of time, the first switch unit and the fourthswitch unit are turned on while the second switch unit and the thirdswitch unit are turned off, resulting in the first sub-pixel displayinggrey level according to the grey level signal. During the fifth periodof time, the second switch unit and the third switch unit are turned onwhile the first switch unit and the fourth switch unit are turned off,resulting in the second sub-pixel displaying grey level according to thegrey level signal.

In still another aspect of the present invention, the fourth period oftime and the fifth period of time are successive.

In yet another aspect of the present invention, when the LCD is under 3Dmode, the first controlling signal and the second controlling signal areinversed, the third controlling signal and the fourth controlling signalare inversed.

Compared to conventional art, the LCD in the present invention adds aplurality of switch units to every row of scan lines while no additionalgate driver is added. The plurality of switch units separately controlcharging and charge sharing of pixel units, therefore pixel charging andcharge sharing are separately controlled. Hence the present inventionfixes flicker in 3D image display while no additional gate driver isadded.

These and other features, aspects and advantages of the presentdisclosure will become understood with reference to the followingdescription, appended claims and accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagram of an LCD displaying 3D image according toa first embodiment of the present invention.

FIG. 2 is a diagram of an enlarged section of the LCD panel in FIG. 1.

FIG. 3 is a timing diagram of controlling signal GW1-GW4 and chargesharing signal GS1-GS2 which are indicated in FIG. 2 under 2D mode.

FIG. 4 is a timing diagram of the controlling signals GW1˜GW4 and thecharge sharing signals GS1˜GS2 under 3D mode of FIG. 2.

FIG. 5 shows a schematic diagram of an LCD capable of showing 3D imagesaccording to a second embodiment of the present invention.

FIG. 6 is a diagram of an enlarged section of the LCD panel in FIG. 5.

FIG. 7 is a timing diagram of the controlling signals GW1˜GW6 under 2Dmode of FIG. 6.

FIG. 8 is a timing diagram of the controlling signals GW1˜GW6 under 3Dmode of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures.

Please refer to FIG. 1, FIG. 1 illustrates a diagram of an LCD 100displaying 3D image according to a first embodiment of the presentinvention. Users are able to switch 2D and 3D images while watching theLCD 100. The LCD 100 comprises a processing unit 102, a plurality ofsource drivers 106, a plurality of gate drivers 108, a timing controller112, a controlling signal generator 114, an input interface 116, a datacontrolling signal generator 118, a charge sharing signal source 115 andan LCD panel 110. The LCD panel 110 comprises a plurality of pixel units130 and a substrate 140.

The processing unit 102 is central processor of personal computers orlaptops to generate signal of a plural frames of 2D and 3D images. Theinput interface 116 is input device users control, such as buttons setup on the LCD 100 or menu displayed on the LCD 100 which selectsinitiate signal of 2D/3D image according to users' input command. Theprocessing unit 102 is electrically connected to the input interface 116and outputs signal of a plural frames of 2D or 3D images to the timingcontroller 112. The controlling signal generator 114 is electricallyconnected to the processing unit 102 and generates different controllingsignal GW1-GW4 according to initiate signal of 2D/3D images. The datacontrolling signal generator 118 is electrically connected to theprocessing unit 102 and generates different data controlling signal DOand DE according to initiate signal of 2D/3D image. The charge sharingsignal source 115 generates different charge sharing signals GS1-GSm.Every row of the pixel units 130 is corresponded to charge sharingsignals GS1-GSm respectively.

The timing controller 112 is electrically connected to the processingunit 102 and generate frequency pulse signal to the gate driver 108, andalso converse received 2D or 3D image signal into 2D or 3D data signal.The gate driver 108 outputs scan signal according to frequency pulsesignal, and the source driver 106 converse signal above into grey levelsignal of different charge level. The source driver 106 and the gatedriver 108 are set up on a chip on film (COF) (non-illustrated) or achip of glass (COG) 140, and electrically connected through the COF. Thegate driver 108 sends scan signal to every row of pixel units 130 insequence through scan lines G1˜Gm. Every row of the pixel units 130display different grey level according to grey level signal from thesource driver 106 through data lines D1˜Dn after receiving scan signal.

Please refer to FIG. 2, a diagram of an enlarged section of the LCDpanel 110 in FIG. 1. The plurality of pixel units 130 on the LCD panel110 are one-to-one electrically connected to data lines D1˜Dn and scanlines G1-Gm. Every pixel unit 130 comprises a first sub-pixel 131 and asecond sub-pixel 132. The first sub-pixel 131 comprises a firsttransistor 1311 and a first electrode 1312. The second sub-pixel 132comprises a second transistor 1321 and a second electrode 1322. The LCD100 also comprises a plurality of switch units and a plurality of dataswitches. Every row of pixel units 130 is electrically connected to oneswitch unit, and every column of pixel units 130 is electricallyconnected to one data switch. Every switch unit comprises a first switchSW1, a second switch SW2, a third switch SW3 and a fourth switch SW4.Every data switch comprises a first data switch S1 and a second dataswitch S2. As every pixel unit 130 is electrically connected to similarelements, the following embodiment takes one pixel unit 130 as instance.

Please refer to FIG. 2 and FIG. 3. FIG. 3 is a timing diagram ofcontrolling signal GW1-GW4 and charge sharing signal GS1-GS2 which areindicated in FIG. 2 under 2D mode. The first data switch S1 iselectrically connected to the data line D1 and the first sub-pixel 131to conduct data signal from the data line D1 to the first sub-pixel 131when receiving the first data controlling signal DO. The second dataswitch S2 is electrically connected to the data line D1 and the secondsub-pixel 132 to conduct data signal from the data line D1 to the secondsub-pixel 132 when receiving the second data controlling signal DE. Thefirst switch unit SW1 is electrically connected to the scan line G1 andthe first sub-pixel 131 to conduct scan signal from the scan line G1 tothe first sub-pixel 131 when receiving the first controlling signal GW1.The second switch unit SW2 is electrically connected to a constantvoltage Vg1 and the first sub-pixel 131 to conduct constant voltage Vg1to the first sub-pixel 131 when receiving the second controlling signalGW2. The third switch unit SW3 is electrically connected to the scanline G1 and the second sub-pixel 132 to conduct scan signal to thesecond sub-pixel 132 when receiving the third controlling signal GW3.The fourth switch unit SW4 is electrically connected to a constantvoltage Vg1 and the second sub-pixel 132 to conduct constant voltage Vg1to the second sub-pixel 132 when receiving the fourth controlling signalGW4. The plurality of charge sharing switches CSW are electricallyconnected to the charge sharing source GS1, the first sub-pixel 131 andthe second sub-pixel 132 and electrically connects the first sub-pixel131 to the second sub-pixel 132 when receiving charge sharing signal andare turned on. Preferably, the constant voltage Vg1 must be at low leveland incapable of turning on the charge sharing switches CSW. The switchunits SW1-SW6, the charge sharing switches CSW and the data switches S1and S2 are N-type metal oxide semiconductor (NMOS) transistors or P-typemetal oxide semiconductor (PMOS) transistors.

When users keep the LCD 100 under 2D mode by input command through theinput interface 116, the processing unit 102 initiates signal accordingto 2D images generated by that command, meanwhile the timing controller112, the controlling signal generator 114 and the data controllingsignal generator 119 provide 2D images with relevant signals. The scanlines G1˜Gn send scan signals to every row of pixel units 130 insequence, the process of which comprises a first period of time T1, asecond period of time T2, and a third period of time T3. The firstperiod of time T1, the second period of time T2, and the third period oftime T3 are successive. When frame rate of the LCD 100 is 60 Hz, the sumof the first period of time T1, the second period of time T2, and thethird period of time T3 is 8.3 ms ( 1/60).

Take the first scan line G1 as instance. In the first period of time T1,the first data controlling signal DO, the first controlling signal GW1and the fourth controlling signal GW4 are at high level. The second datacontrolling signal DE, the second controlling signal GW2, the thirdcontrolling signal GW3 and the charge sharing signal GS1 are at lowlevel. Then the first data switch S1, the first switch unit SW1 and thefourth switch unit SW4 are turned on, meanwhile the second data switchS2, the second switch unit SW2, the third switch unit SW3, the fifthswitch unit SW5 and the plurality of charge sharing units CSW are turnedoff. In this moment, the first sub-pixel 131 displays grey level basedon the grey level signal generated by the source driver 106.

In the second period of time T2, the second data controlling signal DE,the second controlling signal GW2 and the third controlling signal GW3are at high level. The first data controlling signal DO, the firstcontrolling signal GW1, the fourth controlling signal GW4 and the chargesharing signal GS1 are at low level. Then the second data switch S2, thesecond switch unit SW2 and the third switch unit SW3 are turned on,meanwhile the first data switch S1, the first switch unit SW1, thefourth switch unit SW4 and the plurality of charge sharing units CSW areturned off. In this moment, the second sub-pixel 132 displays grey levelbased on the grey level signal generated by the source driver 106.

In the third period of time T3, the second controlling signal GW2, thefourth controlling signal GW4 and the charge sharing signal GS1 are athigh level. The first controlling signal GW1 and the third controllingsignal GW3 are at low level. Then the second switch unit SW2, the fourthswitch unit SW4 and the plurality of charge sharing switches CSW areturned on. The first switch unit SW1 and the third switch unit SW3 areturned off. The source driver 106 does not send grey level signal to thedata line D1, however the first pixel electrode and the second electrodeare at the same level and hence share charge due to turning on of theplurality of charge sharing switches CSW.

Please refer to FIG. 2 and FIG. 4. FIG. 4 is a timing diagram of thecontrolling signals GW1˜GW4 and the charge sharing signals GS1˜GS2 under3D mode of FIG. 2. When users keep the LCD 100 under 3D mode by inputcommand through the input interface 116, the processing unit 102controls the timing controller 112, the controlling signal generator 114and the data controlling signal generator 119 to provide relevantsignals of 3D image in response to a 3D image enabling signal generatedby input command. The scan lines G1˜Gn send scan signals to every row ofpixel units 130 in sequence, the process of which comprises a fourthperiod of time T4, a fifth period of time T5, and a sixth period of timeT6. The fourth period of time T4, the fifth period of time T5, and thesixth period of time T6 are successive.

In the fourth period of time T4, the first data controlling signal DO,the first controlling signal GW1 and the fourth controlling signal GW4are at high level. The second data controlling signal DE, the secondcontrolling signal GW2, the third controlling signal GW3 and the chargesharing signal GS1 are at low level. Then the first data switch S1, thefirst switch unit SW1 and the fourth switch unit SW4 are turned on,meanwhile the second data switch S2, the second switch unit SW2, thethird switch unit SW3, the fifth switch unit SW5 and the plurality ofcharge sharing units CSW are turned off. In this moment, the firstsub-pixel 131 displays grey level based on the grey level signalgenerated by the source driver 106.

In the fifth period of time T5, the second data controlling signal DE,the second controlling signal GW2 and the third controlling signal GW3are at high level. The first data controlling signal DO, the firstcontrolling signal GW1, the fourth controlling signal GW4 and the chargesharing signal GS1 are at low level. Then the second data switch S2, thesecond switch unit SW2 and the third switch unit SW3 are turned on,meanwhile the first data switch S1, the first switch unit SW1, thefourth switch unit SW4 and the plurality of charge sharing units CSW areturned off. In this moment, the second sub-pixel 132 displays grey levelbased on the grey level signal generated by the source driver 106.

In the sixth period of time T6, the second controlling signal GW2 andthe fourth controlling signal GW4 are at high level. The firstcontrolling signal GW1, the third controlling signal GW3 and the chargesharing signal GS1 are at low level. Then the second switch unit SW2,and the fourth switch unit SW4 are turned on. The first switch unit SW1,the third switch unit SW3 and the plurality of charge sharing switchesCSW are turned off. The source driver 106 does not send grey levelsignal to the data line D1. Because the LCD 100 does not initiate chargesharing under 3D mode, the charge sharing signal GS1˜GSm is continuouslyat low level under 3D mode, resulting in continuous turning off of theplurality of charge sharing switches CSW.

In sum, the LCD 100 in the present invention adds a plurality of switchunits to every row of scan line while no additional gate driver isadded. The plurality of switch units separately control charging andcharge sharing of pixel units, therefore pixel charging and chargesharing are separately controlled. Hence the present invention fixesflicker in 3D image display while no additional gate driver is added.

Please refer to FIG. 5. FIG. 5 shows a schematic diagram of an LCD 200capable of showing 3D images according to a second embodiment of thepresent invention. The LCD 200 is a 2D/3D switchable LCD. Differing fromLCD 100, the LCD 200 comprises a controlling signal generator 114 forgenerating different controlling signals GW1-GW6 according to 2D/3Denabling signal.

Please refer to FIG. 6, a diagram of an enlarged section of the LCDpanel 110 in FIG. 5. The plurality of pixel units 130 on the LCD panel110 are one-to-one electrically connected to data lines D1˜Dn and scanlines G1-Gm. Every pixel unit 130 comprises a first sub-pixel 131 and asecond sub-pixel 132. The first sub-pixel 131 comprises a firsttransistor 1311 and a first electrode 1312. The second sub-pixel 132comprises a second transistor 1321 and a second electrode 1322. The LCD200 also comprises a plurality of switch units and a plurality of dataswitches. Every row of pixel units 130 is electrically connected to oneswitch unit, and every column of pixel units 130 is electricallyconnected to one data switch. Every switch unit comprises a first switchSW1, a second switch SW2, a third switch SW3, a fourth switch SW4, and afifth switch SW5, and a sixth switch SW6. Every data switch comprises afirst data switch S1 and a second data switch S2. As every pixel unit130 is electrically connected to similar elements, the followingembodiment takes one pixel unit 130 as instance.

Please refer to FIG. 6 and FIG. 7. FIG. 7 is a timing diagram ofcontrolling signals GW1-GW6 and charge sharing signal GS1-GS2 which areindicated in FIG. 6 under 2D mode. The first data switch S1,electrically connected to the data line D1, is used for conducting datasignal from the data line D1 to the first sub-pixel 131 when receivingthe first data controlling signal DO. The second data switch S2,electrically connected to the data line D1 and the second sub-pixel 132,is used for conducting data signal from the data line D1 to the secondsub-pixel 132 when receiving the second data controlling signal DE. Thefirst switch unit SW1, electrically connected to the scan line G1 andthe first sub-pixel 131, is used for conducting scan signal from thescan line G1 to the first sub-pixel 131 when receiving the firstcontrolling signal GW1. The second switch unit SW2, electricallyconnected to a constant voltage Vg1 and the first sub-pixel 131, is usedfor conducting constant voltage Vg1 to the first sub-pixel 131 whenreceiving the second controlling signal GW2. The third switch unit SW3,electrically connected to the scan line G1 and the second sub-pixel 132,is used for conducting scan signal to the second sub-pixel 132 whenreceiving the third controlling signal GW3. The fourth switch unit SW4,electrically connected to a constant voltage Vg1 and the secondsub-pixel 132, is used for conducting constant voltage Vg1 to the secondsub-pixel 132 when receiving the fourth controlling signal GW4. Thefifth switch unit SW5, electrically connected to the scan line G1 and aplurality of charge sharing switches CSW, is used for conducting scansignal to turn on the charge sharing switches CSW when receiving thefifth controlling signal GW5. The sixth switch unit SW6, electricallyconnected to the constant voltage Vg1 and the plurality of chargesharing switches CSW, is used for conducting the constant voltage Vg1 toturn off the charge sharing switches CSW when receiving the sixthcontrolling signal GW6. Preferably, a magnitude of the constant voltageVg1 must be at low level and incapable of turning on the charge sharingswitches CSW. The switch units SW1-SW6, the charge sharing switches CSWand the data switches S1 and S2 are N-type metal oxide semiconductor(NMOS) transistors or P-type metal oxide semiconductor (PMOS)transistors.

When users keep the LCD 200 under 2D mode by input command through theinput interface 116, the processing unit 102 initiates signal accordingto 2D images generated by that command, meanwhile the timing controller112, the controlling signal generator 114 and the data controllingsignal generator 119 provide 2D images with relevant signals. The scanlines G1˜Gn send scan signals to every row of pixel units 130 insequence, the process of which comprises a first period of time T1, asecond period of time T2, and a third period of time T3. The firstperiod of time T1, the second period of time T2, and the third period oftime T3 are successive. When frame rate of the LCD 200 is 60 Hz, the sumof the first period of time T1, the second period of time T2, and thethird period of time T3 is about 8.3 ( 1/60) ms.

Take the first scan line G1 as instance. In the first period of time T1,the first data controlling signal DO, the first controlling signal GW1,the fourth controlling signal GW4, and the sixth controlling signal GW6are at high level. The second data controlling signal DE, the secondcontrolling signal GW2, the third controlling signal GW3 and the fifthcontrolling signal GW5 are at low level. Then the first data switch S1,the first switch unit SW1, the fourth switch unit SW4, and the sixthswitch unit SW6 are turned on, meanwhile the second data switch S2, thesecond switch unit SW2, the third switch unit SW3, the fifth switch unitSW5 and the plurality of charge sharing units CSW are turned off. Inthis moment, the first sub-pixel 131 displays grey level based on thegrey level signal generated by the source driver 106.

In the second period of time T2, the second data controlling signal DE,the second controlling signal GW2, the third controlling signal GW3, andthe sixth controlling signal GW6 are at high level. The first datacontrolling signal DO, the first controlling signal GW1, the fourthcontrolling signal GW4, and the fifth controlling signal GW5 are at lowlevel. Then the second data switch S2, the second switch unit SW2, thethird switch unit SW3, the sixth switch unit SW6 are turned on,meanwhile the first data switch S1, the first switch unit SW1, thefourth switch unit SW4, the fifth switch units SW5, and the plurality ofcharge sharing units CSW are turned off. In this moment, the secondsub-pixel 132 displays grey level based on the grey level signalgenerated by the source driver 106.

In the third period of time T3, the second controlling signal GW2, thefourth controlling signal GW4 and the fifth controlling signal GW5 areat high level. The first controlling signal GW1, the third controllingsignal GW3, and the sixth controlling signal GW6 are at low level. Thenthe second switch unit SW2, the fourth switch unit SW4, and the fifthswitch unit SW5 are turned on. The first switch unit SW1, the thirdswitch unit SW3, and the sixth switch SW6 are turned off. The sourcedriver 106 does not send grey level signal to the data line D1, howeverthe fifth switch SW5 conducts the scan signal to turn on the pluralityof charge sharing switches CSW. Since the plurality of charge sharingswitches CSW are turned on to electrically connect the first pixelelectrode and the second electrode, the first pixel electrode and thesecond electrode are at the same level to realizing share charge.

Please refer to FIG. 8. FIG. 8 is a timing diagram of the controllingsignals GW1˜GW6 under 3D mode of FIG. 6. When users keep the LCD 200under 3D mode by input command through the input interface 116, theprocessing unit 102 controls the timing controller 112, the controllingsignal generator 114 and the data controlling signal generator 119 toprovide relevant signals of 3D image in response to a 3D image enablingsignal generated by input command. The scan lines G1˜Gn send scansignals to every row of pixel units 130 in sequence, the process ofwhich comprises a fourth period of time T4, a fifth period of time T5,and a sixth period of time T6. The fourth period of time T4, the fifthperiod of time T5, and the sixth period of time T6 are successive.

In the fourth period of time T4, the first data controlling signal DO,the first controlling signal GW1, the fourth controlling signal GW4, andthe sixth controlling signal GW6 are at high level. The second datacontrolling signal DE, the second controlling signal GW2, the thirdcontrolling signal GW3 and the fifth controlling signal GW5 are at lowlevel. Then the first data switch S1, the first switch unit SW1, thefourth switch unit SW4, and the sixth switch unit SW6 are turned on,meanwhile the second data switch S2, the second switch unit SW2, thethird switch unit SW3, the fifth switch unit SW5 and the plurality ofcharge sharing units CSW are turned off. In this moment, the firstsub-pixel 131 displays grey level based on the grey level signalgenerated by the source driver 106.

In the fifth period of time T5, the second data controlling signal DE,the second controlling signal GW2, the third controlling signal GW3, andthe sixth controlling signal GW6 are at high level. The first datacontrolling signal DO, the first controlling signal GW1, the fourthcontrolling signal GW4 and the fifth controlling signal GW5 are at lowlevel. Then the second data switch S2, the second switch unit SW2, thethird switch unit SW3, and the sixth switch unit SW6 are turned on,meanwhile the first data switch S1, the first switch unit SW1, thefourth switch unit SW4 and the plurality of charge sharing units CSW areturned off. In this moment, the second sub-pixel 132 displays grey levelbased on the grey level signal generated by the source driver 106.

In the sixth period of time T6, the second controlling signal GW2, thefourth controlling signal GW4, and the sixth controlling signal GW6 areat high level. The first controlling signal GW1, the third controllingsignal GW3 and the fifth controlling signal GW5 are at low level. Thenthe second switch unit SW2, the fourth switch unit SW4, and the sixthswitch unit SW6 are turned on. The first switch unit SW1, the thirdswitch unit SW3 and the fifth switch unit SW5 are turned off. The sourcedriver 106 does not send grey level signal to the data line D1. Becausethe LCD 200 does not initiate charge sharing under 3D mode, the sixthswitch unit SW6 keeps conducting the constant voltage Vg1 under 3D mode,resulting in continuous turning off of the plurality of charge sharingswitches CSW.

In sum, the LCD 200 in the present invention adds a plurality of switchunits to every row of scan line while no additional gate driver isadded. The plurality of switch units separately control charging andcharge sharing of pixel units, therefore pixel charging and chargesharing are separately controlled. Hence the present invention fixesflicker in 3D image display while no additional gate driver is added.

The embodiments merely takes NMOS transistors as instance. However, aperson having ordinary skill in the art is capable of using PMOS in lieuof NMOS.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements made withoutdeparting from the scope of the broadest interpretation of the appendedclaims.

What is claimed is:
 1. A liquid crystal display (LCD) fixing flicker in3D image display, comprising: a scan line for sending a scan signal; adata line for sending a grey level signal; pixel units comprising afirst sub-pixel and a second sub-pixel; a data controlling signalgenerator for generating a first data controlling signal and a seconddata controlling signal; a controlling signal generator for generating afirst controlling signal, a second controlling signal, a thirdcontrolling signal and a fourth controlling signal; a charge sharingsignal source for generating charge sharing signal; a first data switch,electrically connected to the data line and the first sub-pixel, forconducting the grey level signal to the first sub-pixel when receivingthe first data controlling signal; a second data switch, electricallyconnected to the data line and the second sub-pixel, for conducting thegrey level signal to the second sub-pixel when receiving the second datacontrolling signal; a first switch unit, electrically connected to thescan line and the first sub-pixel, for conducting the scan signal to thefirst sub-pixel when receiving the first controlling signal; a secondswitch unit, electrically connected to a constant voltage and the firstsub-pixel, for conducting the constant voltage to the first sub-pixelwhen receiving the second controlling signal; a third switch unit,electrically connected to the scan line and the second sub-pixel, forconducting the scan signal to the second sub-pixel when receiving thethird controlling signal; a fourth switch unit, electrically connectedto the constant voltage and the second sub-pixel, for conducting theconstant voltage to the second sub-pixel when receiving the fourthcontrolling signal; and a charge sharing switch, electrically connectedto the charge sharing signal source, the first sub-pixel and the secondsub-pixel, for electrically connecting the first sub-pixel to the secondsub-pixel when receiving the charge sharing signal and turning on. 2.The LCD of claim 1, wherein a process of the scan line sending the scansignal to the pixel units comprises a first period of time, a secondperiod of time and a third period of time when the LCD is under 2D imagemode; during the first period of time, the first data switch, the firstswitch unit and the fourth switch unit are turned off while the seconddata switch, the second switch unit, the third switch unit and thecharge sharing switch are turned off, resulting in the first sub-pixeldisplaying grey level according to the grey level signal; during thesecond period of time, the second data switch, the second switch unitand the third switch unit are turned on while the first data switch, thefirst switch unit, the fourth switch unit and the charge sharing switchare turned off, resulting in the second sub-pixel displaying grey levelaccording to the grey level signal; and during the third period of time,the second switch unit, the fourth switch unit and the charge sharingswitch are turned on while the first switch unit and the third switchunit are turned off, resulting in the first sub-pixel electricallyconnecting to the second sub-pixel.
 3. The LCD of claim 2, wherein thefirst period of time, the second period of time and the third period oftime are successive.
 4. The LCD of claim 2, wherein the charge sharingsignal is the scan signal, the controlling signal is also generating thefifth controlling signal and the sixth controlling signal, and the LCDfurther comprises: a fifth switch unit, electrically connected to thescan line and the charge sharing switch, for conducting the scan signalto turn on the charge sharing switch when receiving the fifthcontrolling signal; a sixth switch unit, electrically connected to theconstant voltage, for conducting the constant voltage to turn off thecharge sharing switch when receiving the sixth controlling signal. 5.The LCD of claim 4, wherein when the LCD is under 2D mode, the fifthswitch unit is turned off while the sixth switch unit is turned on toconduct the constant voltage during the first and second periods oftime; the fifth switch unit is turned on to conduct the scan signalwhile the sixth switch unit is turned off during the third period oftime.
 6. The LCD of claim 4, wherein when the LCD is under 2D mode, thefirst controlling signal and the second controlling signal are inversed,the third controlling signal and the fourth controlling signal areinversed, and the fifth controlling signal and the sixth controllingsignal are inversed.
 7. The LCD of claim 4, wherein when the LCD isunder 3D mode, the fifth switch unit and the sixth switch unit areturned off.
 8. The LCD of claim 4, wherein a process of the scan linesending the scan signal to the pixel units comprises a fourth period oftime and a fifth period of time when the LCD is under 3D image mode;during the fourth period of time, the first switch unit and the fourthswitch unit are turned on while the second switch unit and the thirdswitch unit are turned off, resulting in the first sub-pixel displayinggrey level according to the grey level signal; and during the fifthperiod of time, the second switch unit and the third switch unit areturned on while the first switch unit and the fourth switch unit areturned off, resulting in the second sub-pixel displaying grey levelaccording to the grey level signal.
 9. The LCD of claim 8, wherein thefourth period of time and the fifth period of time are successive. 10.The LCD of claim 8, wherein when the LCD is under 3D mode, the firstcontrolling signal and the second controlling signal are inversed, thethird controlling signal and the fourth controlling signal are inversed.